In recent years, the design of the composite structure of a bituminous pavement in China is often finished based on utilization experience. The checking computation of the design of pavement deflection for characterizing the pavement bearing capability is often realized by an inverse method. The premise of the inverse method is that the modulus of each structural layer material is a fixed value. However, the test of the mechanical property of the material often indicates that the modulus of the material is greatly fluctuated along with the differences of the material properties and composition designs. To satisfy the deflection design, a high-strength semi-rigid base layer will be adopted by numerous construction companies. The modulus of the high-strength semi-rigid base layer greatly exceeds a recommended value of a design specification, which also causes that the rebound deflection of each structural layer satisfies the design requirement in the acceptance process of the current bituminous pavement. However, the bituminous pavement generates the damage of reflection of cracks, ruts and the like in the early service process.
It is believed from the current theoretical and practical studies that the reason for generating such damage is inadequate high temperature stability of the bituminous surface layer. Therefore, various measures for improving the high temperature performance of the bituminous surface layer arise at the historic moment, mainly including high-performance SBS modified bituminous mixture, high-modulus bituminous mixture, etc. However, with the continuous increase of road grades and vehicle speed, the growth of traffic and the increase of axle load in recent years, the early damage of the pavement still does not obtain an expected improvement effect. The reason for this is not just inadequate high temperature stability of the bituminous surface layer material, but excessively large rigidity of the semi-rigid base layer and mismatching with the modulus of the bituminous surface layer. With the increase of the modulus of the semi-rigid base layer, the tensile stress between bituminous pavement layers is increased, which is easy to cause early shear damage to the bituminous pavement. In order to solve the mismatching problem between the modulus of the semi-rigid base layer and the modulus of the bituminous surface layer material, two measures of installing a structural layer between both of the moduli and increasing the modulus of the entire bituminous surface layer material can be taken.